Abstract
PURPOSE: To examine the longitudinal relationship between the age or shelf-life of common type 2 diabetes laboratory tests for serum creatinine, cholesterol, and glycated hemoglobin A1c conducted in outpatient settings and subsequent inpatient hospitalizations and emergency department visits. METHODS: This study analyzes panel data from two healthcare delivery systems' electronic health records (EHR) for patients aged 18 years and older managing type 2 diabetes. We used EHR data to quantify the age of three laboratory tests: serum creatinine, cholesterol, and glycated hemoglobin A1c. Encounter data were used to determine the frequency of inpatient hospitalizations and emergency department visits. Negative binomial regressions with fixed effects were performed to compute marginal effects, levels of statistical significance, and 95% confidence intervals. RESULTS: The average age for serum creatinine laboratory tests was 1.51 months (95%CI: 1.49-1.53). We computed older average ages for hemoglobin A1c (mean:6.17 months; 95%CI: 6.11-6.23) and serum creatinine tests (mean: 8.73; 95%CI: 8.65-8.81). Older laboratory tests were associated with an increase in the total expected counts of subsequent inpatient hospitalizations (ME = 0.047; p < 0.001) and ED visits (ME = 0.034; p < 0.001). CONCLUSION: Findings from this study indicate that older type 2 diabetes laboratory tests are associated with increases in the total expected count of subsequent inpatient hospitalizations and emergency department visits. Future research should examine the actionability of laboratory test values to determine associations with healthcare outcomes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40200-023-01250-0.